Hi Brian!
You can change the expression of the BooleanExpression trough the Modelica Text View. However, since that component only has a connector it won't show up in the parameters nor variables tab.
e.g.
Modelica.Blocks.Sources.BooleanExpression booleanExpression(y = pulse.y and step.y and time >= 5)
Note also that the examples are read-only but you can create a duplicate to work with, right click on the class in the class browser and choose 'Duplicate'.
